Method of making rubber heels



July 12, 1932. F BEREN$TE|N 1,867,132

METHOD OF MAKING RUBBER HEELS Filed Feb. 6, 1931 UNi'rEns'rrs Ar Patented July 12, 1932 ice FRANK BnRnns'rErn, or CHELSEA, MAssAoI-wsn'rrs, assre'non To-renco RUBBER COMPANY, or CHELSEA, mnssaonnsn'rrs, A CORPORATIOH or MAssaonnsE'rrs mnrnon on MAKING R BBER Tennis 7 Application filed February 6, 1931. Serial K015513541.

The present invention relates to a method of producing rubber heels, and more part1cu larly to such a method designed primarily for the production of rubber heels with embedded plugs employed for ornamental or non-slipping purposes.

The purpose of the invention is to produce heels of this character by a new and improved method which insures the proper 1ocation and conformation of the individual plugs, and at the same time unites the plugs firmly in the body of the finished heel.

To the accomplishment of this purpose I propose to employ a heel mold which may be made in three parts as is usual, and provided with mold pins for receiving and locating the plugs and accompanying washers.

In producing the heel one or more plugs severed or cut from a length of tubing of proper dimensions is placed upon a mold pin and surmounted by a cupped washer of somewhat larger diameter than the plug. After the requisite number of plugs and washers have been assembled, a blank of uncured rubber composition is placed thereover, and the mold assembled and the contents subjected to temperature and pressure. In the process of vulcanizing, the rubber of the blank is caused to flow about the plugs and washers. The material of the plug, which is also uncured rubber, preferably with a friction material combined therewith, is prevented from substantial deformation by the conjoint action of the cupped washer at one end of the plug,

and the reception of the opposite end of the plug in a positioning recess in the mold. The washer and recess combine to prevent splaying out or gross deformation of the uncured plug during the vulcanizing pressure, at the same time permitting the rubber of the heel blank to flow therearound and to be effectually bonded to the plug and accompanying wash-- er. The mold pins are ordinarily provided with washer-receiving shoulders for positioning the washer within the finished heel, as is customary.

In the actual construction of the heel it is proposed to provide friction plugs about a portion of the nail-receiving recesses, the re-' maining. being supplied merely with washers in the usual manner. Asindicated, the 'recesses having no plugs may be provided with ornamental projections similar in appearance to the projecting portion of the plug.

In the accompanying drawing illustrating the best method of practicing the invention, Fig. 1 is a plan view of the mold plate containing the washer-locating pins and determining the configuration of the'tread' face of the heel; Fig. 2 is a section through a mold cavity, illustrating the placing of the plugs and washers thereon and the location of the heel blank before pressure is applied; Fig. 3 is a section of the same cavity after the molding operation has been completed, with.

the heel contained therein; Fig. 4 is a plan View of the finished heel; and Fig. 5 is av detail showing one of the plugs ready for application to a mold pin. a

In carrying out the present process, as

shown in the illustrated embodiment of the invention, the plugs 10, preferably cut from a length of tubing, are dropped over all or a portion of the mold pins 12, centering in the co11cavereces'ses'14 formed at the base of the mold pins in the bottom 16 of the mold cavity. The configuration of these recesses 14 determines the appearance and conformation of the plugs in the finished heel. superime posed over each plug is'a concave washer 18, slightly larger'than the plug and adapted when pressure is applied to the mold to seat upon a shoulder 20 formed on the mold pin. In this position of the washer it will be evident that-the. pluglis engaged atopposite.

ends by the washer and recess 14, and that due to the proximity of the washer and recess, the plug is substantially encompassed thereby and is actually held against any major distortion due to the pressures employed in the vulcanizing operation. In other words, the assembly serves to retain the form of the plugs in their general dimensions, and pre-- vents flowing of the plugs into the body of the heel during vulcanization, It does not, however, prevent or interfere with the-flowing of the heel body therearound, and'the proper bonding of the heel body to the embedded washer and plug. 7 i As shown in the illustrated embodiment of maining pins are provided with nail-receiv- CTI ing washers, which maybe and preferably are of smaller size than the washers which surmount the frictionwplugs. These washers are indlcated at 22. r

After the completion of the article, as

shown particularly in Fig.3, the heel is provided with a series of embedded washers, and

with one or more embeddedfriction plugs which, during the vulcanizing operation, are 1 'ly into the concave recesses and conforming therewith while held against further deforbondedand united with the surrounding heel body. These plugs may preferably have combined with the rubber composition a certaln amount of fibrous material for increasing the frictional qualities, and in the illustrated embodiment of the invention are preferably compounded of a different-color from the major portion of the heel body. The plugs are inserted in the molds in an unvulcanized state, together with the heel blank, so that the single operation completely bonds and vulcanizes both the body and embedded plugs at one and the same time. At its completion the finished heel has the general surface appearance indicated at 25; in Fig. 4. This heel has a series of nail-receiving recesses extending completely about the peri-aher certain of these recesses bein rovided and surrounded with embedded fric tion plugs. The remaining recesses are merely provided with washers, but may have embossed protuberances at the tread surface to improve the appearance ofthe heel, and

cause these recesses to conform in general ap-' pearance with the tread POItlOIl Of the plugs.

imposing over each tube and supported theremold cavity provided with a surrounding by a concave washer of larger diameter than that of the tube, assembling an unvulcanized rubber heel blank above the pins, and subjecting the entire assembly to heat and pressure for the purpose of simultaneously forcing the heel blank over the pins, washers and tubes and the washers on to the shouldered portions of the pins, with the tubes forced downwardly into the recesses and conforming therewithwhile held against further deformation at oppositeends, by the washers and recesses vrespectively. v

2. The method of making rubber heels provided with inserted plugs whichconsists in assembling oneor more unvulcanized rubber tubes of generally cylindrical form over shouldered positioning pins in the plate ofa blank above the pins, and subjecting the entire assembly to heat and pressure 'for the purpose of simultaneously forcing the heel blank over the pins, washers and tubes and the washers on to the shouldered portions of the pins, with the tubes forced downwardmation at opposite ends by the washers and con-cave recesses respectively.

In testimony whereof I have signed my name to thislspecification.

ANK Bissau-STEIN. Y' 

